Abstract: An extracorporeal blood processing system is disclosed which includes a variety of novel components and which may be operated in accordance with a variety of novel methodologies. For instance, the system includes a graphical operator interface which directs the operator through various aspects of the apheresis procedure. Moreover, the system also includes a variety of features relating to loading a blood processing vessel into a blood processing channel and removing the same after completion of the procedure. Furthermore, the system also includes a variety of features relating to utilizing a blood priming of at least portions of the apheresis system in preparation for the procedure. In addition, the system includes a variety of features enhancing the performance of the apheresis system, including the interrelationship between the blood processing vessel and the blood processing vessel and the utilization of high packing factors for the procedure.

Abstract: A flow rate of a fluid flowing in a tube is quantitatively determined by altering the electrical conductivity of the fluid by injection of a bolus of saline. The electrical conductivity of the altered conductivity is measured over the time it takes the altered conductivity fluid to pass a conductivity measuring location. The measured conductivity is integrated over the time it take to pass the conductivity measuring location. The integral is interpreted to determine the flow rate.

Abstract: A combination pressure pod and access site apparatus is suitable for use in a medical tubing set. The combination pressure pod and access site comprises a pressure sensing chamber and a measured fluid chamber separated by a pressure transmissive diaphragm. An access site having a needle or needle-less septum is in fluid communication with the measured fluid chamber and permits and withdrawing fluids from, the measured fluid chamber through the access site. One or more of the combination pressure sites and access sites may be provided in a simplified blood tubing set for an extracorporeal blood treatment apparatus, such as a hemodialysis apparatus.

Abstract: A high quality, low hydrogen content, hydrogenated amorphous silicon (a-Si:H) film is deposited by passing a stream of silane gas (SiH.sub.4) over a high temperature, 2000.degree. C., tungsten (W) filament in the proximity of a high temperature, 400.degree. C., substrate within a low pressure, 8 mTorr, deposition chamber. The silane gas is decomposed into atomic hydrogen and silicon, which in turn collides preferably not more than 20-30 times before being deposited on the hot substrate. The hydrogenated amorphous silicon films thus produced have only about one atomic percent hydrogen, yet have device quality electrical, chemical, and structural properties, despite this lowered hydrogen content.